Are you supplying any type of ammonia? If not, the bacteria will just die off... Feed the tank as you would if you have fish, but very limited portions. Why would there be a spike in anything if all you added was bacteria?

Like beetle I don't have experience with Bio-Spira either. A quick google search however brings out 2 sides of the coin: some swear by it, others think it's junk. Since it's in my nature to be skeptical about "magic cure-all" products, I tend to be skeptical about any product that claims to shorten the natural cycle from weeks to mere days. I would tend to think that Bio-Spira is probably in line with other products that promote good bacteria to aid the cycle (such as Nutrafin Cycle and the like)... but as I've said, I never used Bio-Spira.

Tank mates suggested by beetle are good ones. I've read that Gouramis are compatible with Angels but stay away from smaller fish such as neons, white clouds and guppies... unless you want to give them to your Angels as a snack!

i see that you have a krib with tigers in your tank, im assuming that they are healthy, how is that dynamic working for you?

I've done it once. i had 2 Angels and 1 Betta in a 55g. I've heard to use caution when doing this, but I had no trouble. If you do I would watch closely. It really depends on the fish as some are more passive than others. I've read Angels are more semi-aggressive but I've yet to have one be even slightly aggressive.